Smoth screen changes. Step 1

lib/screens/purchase.dart

@@ -33,11 +33,9 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
 
   TextEditingController bonusController = new TextEditingController();
 
-  PurchaseScreenState(SqliteHelper helper, String app, String userString, String card) {
+  PurchaseScreenState(SqliteHelper helper, String app, String userString, String card) : super(helper, app) {
     this.user = JSON.decode(userString);
     this.card = card;
-    this.helper = helper;
-    this.app = app;
   }
 
   @override
@@ -45,7 +43,7 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
     setState(() {
       requestAsyncData(user);
     });
-    return new WillPopScope(onWillPop: onWillPop, child: getMainWidget());
+    return getMainWidget();
   }
 
   bool purchaseInProgress = false;
@@ -173,15 +171,14 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
         height: buttonHeight,
         child: new FlatButton(
             child: new Text(title, style: new TextStyle(color: textColor)),
-            onPressed: () => startScanner(context, app, helper)),
+          //    FIXME:  onPressed: () => startScanner(context, app, helper)),
+            onPressed: () => print('startScanner')),
         decoration: new BoxDecoration(
             border: new Border.all(
                 color: Resources.getButtonColor(app), width: 1.0),
             borderRadius: new BorderRadius.all(new Radius.circular(4.0))));
   }
 
-
-
   @override
   String getTitle() {
     return StringsLocalization.carryingPurchase();
@@ -424,7 +421,7 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
     print('bonus ' + this.bonus);
   }
 
-  onWillPop() {
-    return startScanner(context, app, helper);
-  }
+//  onWillPop() {
+//    return startScanner(context, app, helper);
+//  }
 }